It is well known that leaded gasoline is a major cause of air pollution which is being combatted in part by requiring newer cars to operate on unleaded gasoline. Whereas older cars still require leaded gasoline, service stations routinely provide both leaded and unleaded gasoline to service both the newer and older cars.
Leaded gasoline is generally cheaper to buy than unleaded gasoline. Also many people feel that their automobile operates better on leaded gasoline. Thus a significant percentage of the people driving the newer cars, if given a choice, will purchase leaded gasoline. To prevent this violation of the Air Pollution Act, a Federal Mandate was devised to force new car owners to purchase unleaded gasoline only.
The Mandate provides that retailers of gasoline use two specifically sized gas pump nozzles, the nozzle for leaded gas being larger than the nozzle for unleaded gas. A second part of the Mandate requires manufacturers to provide the gas tank fill pipes of the newer cars being manufactured with restrictors that will prevent the use of the larger nozzle for pumping gas through that fill pipe into the car's fuel tank.
The restrictor is in effect a secondary spring loaded gas cap that fits inside the fill pipe. The cap is opened by forcing the smaller nozzle through a restricted opening. The nozzle engages and pushes open the spring loaded cap. The gasoline can then be freely pumped through the fill pipe. The larger nozzle will not fit through the restricted opening and thus the cap cannot be pushed open for filling with the leaded gasoline.
A small but significant percentage of new car owners get around these requirements by removing the restrictor in the fill pipe, e.g., with a long chisel type tool and a hammer that is applied to break loose the fasteners securing the restrictor in the fill pipe. However, registration of automobiles often require pollution checks, (notably in metropolitan areas) and one of these checks is for the restrictor in the fill pipe. Without the restrictor the car cannot be registered. Replacing the restrictor has heretofore been a very expensive proposition, e.g., requiring replacement of the fill pipe or even the entire fuel tank.
Whereas the unscrupulous get their just desserts so to speak, a very large percentage of those caught in this dilemma are innocent second party purchasers of the automobile.